Scissor lifts are often operated by lift operators, who are supported in a passenger basket of the scissor lift, into desired positions to allow the operators to accomplish a task or manage a repair on an elevated structure. For example, scissor lifts are used during the inspection, maintenance, and repair of aircraft. Operators generally drive the scissor lift into a desired position alongside a section of an aircraft (or other structure to be inspected or repaired). Once in position near the aircraft structure, the operator elevates the passenger basket to a desired height in order to perform the desired task on the structure.
However, while performing the inspection or repair on the structure, the operator may need to repeatedly adjust the vertical position of the passenger basket and/or repeatedly adjust the horizontal position of the passenger basket by driving the scissor lift to a new location near the structure. These position and location adjustments can result in the operator inadvertently maneuvering the scissor lift into contact with the structure (or into contact with another surrounding object).
Such collisions not only have the potential to cause aesthetic and structural damage to the structure, but may also damage the scissor lift itself. For example, the passenger basket of the scissor lift may collide with the wing of an aircraft, potentially causing substantial damage to the aircraft and requiring an extensive and costly repair. In another example, an object may inadvertently get caught in the scissor extension mechanism, thus damaging the obstructing object and damaging the scissor extension mechanism. Further, the operator may accidentally drive the scissor lift into contact with a structure because the operator did not know and could not see the position (i.e., direction) of the wheels upon moving the lift.
While certain conventional control systems endeavor to prevent scissor lift collisions, such systems are usually difficult to implement, difficult to use, and often cost the operator more time and money than saved.